Graco GM 3500 Instructions-Parts List Manual page 21

WARNING
To reduce the risk of serious bodily injury, always
follow the Pressure Relief Procedure Warning on
page 13 before repairing the sprayer.
NOTE: Refer to Fig 21–1 for this procedure.
1. Remove the front cover (23).
2. Disconnect the hose (59) from the pump nipple (57).
For the upright carts only, detach the drain hose (102)
from the pump.
3. Remove the four screws (73) and lockwashers (74)
from the bearing housing (21).
4. Lightly tap the back of the bearing housing with a plas-
tic mallet. Pull the pump, bearing housing and con-
necting rod away from the drive housing as one
assembly.
5. Remove the two screws (24) and lockwashers (11).
Remove the four screws (10) and lockwashers (11).
6. Lightly tap around the drive housing (20) with a plastic
mallet to loosen it from the pinion housing (19n).
TORQUE TO
175 IN–LB
(20 N.M)
74
73
23
68
Fig 21–1
DRIVE HOUSING
20
22
21
CAUTION
DO NOT drop the gear cluster (18) when removing
the drive housing (20). The gear cluster is easily
damaged. The gear may stay engaged in either the
drive housing or the pinion housing.
DO NOT lose the thrust balls (20c and 19j) located
at each end of the gear cluster. The balls, which are
heavily covered with grease, usually stay in the
shaft recesses, but they could be dislodged. If they
are caught between the gears and not removed, the
balls will seriously damage the drive housing. If the
balls are not in place, the bearings will wear
prematurely.
7. Liberally apply bearing grease (20d, supplied) to the
gear cluster (18). Be sure the thrust balls (20c and
19j) are in place.
8. Place the bronze colored washer (20a) and then the
silver–colored washer (20b) on the shaft protruding
from the big bearing of the drive housing (20). Align
the gears and push the new drive housing straight
onto the pinion housing and locating pins (B).
9. Starting at Step 5, work backwards to reassemble the
sprayer. Or, move ahead to the next section in this
manual if further service is needed.
B
19n
20b
20a
11
24
59
57
102
10
11
11
19j
18
20c
10